Low-fat diets are not the best way to lose weight, a major study says– casting doubt on decades of health advice.
Scientists concluded there is no evidence to support the dogma that people should reduce the amount of fat in their diet.
The study raises further questions about NHS guidelines going back 32 years warning people to avoid butter, full-fat milk and other high-fat foods.
Health officials should give simple guidance focused on portion sizes and unprocessed foods instead of focusing on fat, carbohydrates and proteins, said the researchers from Harvard.
Dr Deirdre Tobias, who led the research based on data from more than 68 000 adults, said: “Therei is no good evidence for recommending low-fat diets.
“Despite the pervasive dogma that one needs to cut fat to lose weight, the scientific evidence does not support low-fat diets over other dietary interventions for long-term weight loss.”
In 1983, British government guidelines advised Britons to cut their fat intake to 30 percent of total energy and increase the amount of carbohydrates they ate.
Critics say this contributed to the boom in “diet” food products, an obsession with calorie counting and a massive weight-loss industry. Emerging evidence suggests that not all types of fat are bad – and some can play a role in protecting the heart and reducing weight.
There is growing interest in Mediterranean diets with high levels of fatty foods such as olive oil, fish and nuts as well as fruit, vegetables and whole grains.
The Harvard team found that cutting back on fat was a less effective route to weight loss than low-carbohydrate or Mediterranean diets. Their study in respected medical journal Lancet Diabetes & Endocrinology, compiles information from 53 previous trials comparing the effectiveness of low-fat diets.
Those on low-carbohydrate diets lost an average 2.5lb (1.15kg) more than those on low-fat diets over 12 months, it showed.
Researchers found that low-fat diets led to a greater weight loss only when compared to a “usual diet” in which participants did not change their eating habits, with a 12lb (5.41kg) difference.
Dr Tobias called for a move towards healthy eating patterns, whole foods and portion sizes. The conclusions were backed by British cardiologist Dr Aseem Malhotra, adviser to the National Obesity Forum.
He said advice to cut fat intake and boost starchy carbohydrates has ‘been a complete failure tackling obesity’.
Dr Malhotra also called for a move to food-based advice.
Not all experts, however, are convinced. Professor Tom Sanders, of King’s College London, said: “To control weight, it remains sensible to eat less and avoid consuming excess amounts of fat and sugar, especially as fatty meat, deep fried foods, cakes and biscuits and sugar-sweetened beverages.”
Daily Mail
Low-fat diets 'not the best way to lose weight'
Adopting a low-fat diet and forgoing crisps and fry-ups may not be the best way to slim, a study has found.
Experts who analysed data on more than 68 000 adults concluded that curbing fat intake did not lead to greater weight loss than low-carbohydrate or Mediterranean diets.
Scientists pulled together information from 53 trials comparing the ability of low-fat and other kinds of diet to help shed unwanted pounds over a period of at least one year. They found no significant difference in average levels of weight loss between reduced-fat and higher-fat diets.
Diets that cut out fat were slightly less effective than those based on lowering carbohydrate consumption, the researchers reported in The Lancet Diabetes & Endocrinology journal.
The Independent